(a) Field of the Invention
This invention relates to valve testing fixtures for testing valves.
(b) Description of the Prior Art
Various industries use different types and sizes of fluid devices, such as valves, which periodically require to be tested to determine their strength, accuracy of workmanship, fluid tightness, as well as their stability for a particular purpose. In order to test such valves, various machines having clamping fixtures have been proposed and used. Such fixtures are described, for example, in U.S. Pat. Nos. 971,191, 3,163,035 and 3,088,312.
The clamping fixtures of the known valve testing machines have different drawbacks, the most important of which are: their parts have an arrangement which is complicated and time-consuming to operate, the parts lose their operative effectiveness in a relatively short time, requiring frequent maintenance and repair; such machines are also limited to a narrow range of valve sizes; and the known machines sometimes act on the entire casting of the test valve and, therefore, frequently damage the valve's structural integrity, and at the same time they obstruct visual inspection of the valve's inside, while the test is in progress.